Device for ejecting a load slung under a high-performance aircraft

ABSTRACT

Device for ejecting a load slung under an aircraft, designed to impart to this load, at the moment of its release, kinematic values controlled as a function of the instantaneous flight parameters of the aircraft at this moment. 
     A plurality of separate modules (1, 2A, 2B, 4, 10) makes it possible, on the one hand, to execute a longitudinal translational movement (d) of the load (3) to detach it from the members (5) attaching it to the aircraft and, on the other hand, to carry out an accurate adjustment of the angular ejection speed. One of the modules is an energy source (1), such as a bottle of compressed nitrogen. Two other modules are respectively a front fluid jack (2A) and a rear fluid jack (2B), both with a retractable telescopic piston which, when the pressurized gas is supplied to it by the source (1), exerts an ejection force on the load (3). 
     The invention is used for the release of loads carried by aircraft.

BACKGROUND OF THE INVENTION

Modern military aircraft carry various loads slung either under thefuselage or under the wings, these loads usually being releasable inflight, mainly when they are bombs or missiles.

To ensure good separation between the load and the aircraft within awide range of its flight conditions, it is not sufficient to detach theload: it is also necessary to impart to it a linear ejection speed Vzand an angular ejection speed ωy. These two quantities Vz and ωy aredetermined by means of ejection tests in a wind tunnel. Their value isnot constant, but is a function of the flight parameters: the Machnumber, altitude, corrected speed, incidence and load factor. Ingeneral, a minimum quantity Vz satisfactory over the entire range can bedefined. This is not true of the quantity ωy which varies greatlyaccording to the flight conditions.

The ejection systems existing at the present time in aeronautics have tobe adjusted on the ground and consequently only have an optimum settingfor a single flight condition at the moment of release.

The object of the present invention is the provision of a modularejection device which is capable, on the one hand, of ensuring ahorizontal translational movement of the missile to disconnect it fromits rail before ejection and, on the other hand, of adjusting theangular ejection speed as a function of the flight parameters.

The following description referring to the attached drawings and givenby way of non-limiting example will make it easy to understand how theinvention can be put into practice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view, in partial longitudinal section,illustrating an embodiment of the present invention.

FIGS. 2 and 3 are sectional views on a larger scale of an embodimentdetail in two operating positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The ejector device illustrated in FIG. 1 consists of an assembly ofseparate modules, each having a particular function:

1. An energy source 1, which can be a bottle of nitrogen compressed at apressure of a few hundred bars and equipped with a pyrotechnic valve, ora pyrotechnic chamber equipped with a gas generator (for example, withstandard fuses);

2. A front jack 2A with a retractable telescopic piston which, when thepressurized gas is supplied to its inlet, exerts an ejection force onthe load carried 3;

3. A rear jack 2B identical to the front jack 2A;

4. A sequential release/ejection module 4 which is supplied by theenergy source 1 and which performs three functions:

a release function by shifting the load 3 in a translational movementout of its rails 5--5 attaching it to the aircraft (the translationalmovement will be an acceleration and stop, in order to bring thetranslational speed of the load 3 back near to zero after it has beenremoved from its rails 5 and before ejection);

an ejection adjustment function which, by means of a servo slide valve 6with a double needle 7A-7B, adjusts the pressure distribution betweenthe front jack 2A and rear jack 2B, to impart to the load 3 an angularpitching speed determined in accordance with the instantaneous flightconditions of the aircraft;

a sequential function to ensure that the ejection thrust of the jacks2A, 2B can only be generated when the movement of acceleration and stopis completed.

These various modules are connected by means of pressurized-gasconduits. More specifically, the energy source 1 is connected to theinlet of the sequential module 4 by means of a conduit 8, whilst theoutlets of the latter, downstream of the needles 7A, 7B, are connectedrespectively to the front jack 2A and to the rear jack 2B by means ofconduits 8A and 8B. The double-needle servo slide valve 6 is controlled,in turn, by the intervention of a transmission link 9 from aservo-module 10 programmed to integrate the various flight parameterswhich are appropriately detected.

The mode of operation of the sequential module 4 described above inrelation to FIG. 1 will be understood better by also referring now toFIGS. 2 and 3, in which the same reference numerals have been used todesignate the same elements.

In addition to these, the drawings also show a rod 11 for pulling theload 3 forwards to detach it from its rails 5, this rod 11 acting on aboss 3A integral with the load 3 by means of an articulated latchmechanism 11A which, at rest (FIG. 2), is kept engaged by an elasticlever stop 11B and which is guided in its longitudinal travel d (FIG. 3)by a carriage 11C. This pull rod 11 interacts with a locking slide 12with retractable balls 12A engaged with a groove 11D made around the rod11, this system being shown in the locked position in FIG. 2 and in theunlocked position in FIG. 3.

The pull rod 11 for the load 3, with its ball locking system 12, isintegral with a drive piston 13 sliding in a chamber 14 opposite abraking piston 15 perforated with a port 15A.

The pressurized gases coming from the bottle 1, which are released bymeans of the pyrotechnic valve, are introduced into the head of thechamber 14 via the conduit 8 and first push the ball locking slide 12 ofthe pull rod 11 to the rear, thereby unlocking the latter. After that,when this rod 11 has been freed in this way, the gases push the drivepiston 13 forwards, thereby driving the load 3 in a translationalmovement, and the displacement of the piston 13 is not impeded by thefluid filling the interspace located between the pistons 13 and 15because of the port 15A made in the latter.

After a certain stroke, the drive piston 13 comes into contact with thebraking piston 15 which it drives in turn, the two pistons 13 and 15then moving together.

The propellant gases coming from the conduit 8 have, from the outset,been introduced into a braking chamber 16 located behind the brakingpiston 15. As soon as the latter is pushed back, it begins to performits braking function, since the gases in the braking chamber 16 arecontained. When both the pistons have executed a specific stroke, atransfer duct 17 is exposed and supplies the pressurized gases to thedouble-needle slide valve 6 which ensures that streams of gas aredispensed towards the ejection jacks 2A, 2B and which at each moment ispositioned, according to a control law linked to the flight parametersof the aircraft, by means of the servo-module 10, to which the slidevalve 6 is connected via the transmission link 9 completed by a crank 9Aintegral with a pinion 9B meshing with the slide valve.

The device which has just been described in terms of its organizationand mode of operation achieves several technical advantages:

The modular nature of the system which can be adapted to loads 3 of verydifferent dimensions and to very diverse carrying structures because thegeometrical positions of the various modules of the system are not laiddown, as they are where a one-piece ejector is concerned.

A high-performance system, because the instantaneous automaticadjustment in flight of the position of the slide valves 6 controllingthe angular ejection speed makes it possible, when a missile is firedduring combat maneuvers, to guarantee the best possible trajectory forthe missile.

The system is very light-weight because: the ejection forces only risein the region of the the ejection jacks 2A,2B, and there is no need forany mechanical control gear, the slide 6 of the distributor is abalanced device which can be controlled with low forces and shortstrokes, and this is beneficial to the smooth operation of thisservo-system,

The effectiveness of the acceleration/stop system because this deviceensures that the missile 3 is removed from its rails 5 as a result of ahorizontal movement over a specific travel d according to anacceleration/deceleration law which puts the missile into the ejectionposition, at a speed near zero, in a minimum amount of time.

This last characteristic prevents any risk of sub-stantial slipping ofthe rods of the ejection jacks 2A, 2B when they exert a thrust on theload 3, and thus eliminates the risks of damage to the jack or to theload, and ensures an initial departing trajectory of the missile 3perpendicular to the missile axis, thereby making it possible to eject amissile semi-housed within the contour of a fuselage without the risk ofcatching when it comes out, with the sole proviso that a clearance of alength equal to the advancing travel d of the missile (a fewcentimeters) be provided in the missile pen.

It goes without saying that the embodiment described is only one exampleand that it could be modified, in particular by substituting technicalequivalents, without thereby departing from the scope of the invention.

We claim:
 1. A mechanism for detaching an elongated load from supportelements located on the underside of an aircraft and for ejecting theelongated load in a controlled manner away from the aircraft, theelongated load having a front end and a rear end, said mechanismcomprisinga front fluid jack module which is attachable to said aircraftand is capable of contacting the front end of said elongated load tomove said front end away from said aircraft at a controlled speed, aseparate rear fluid jack module which is attachable to said aircraft andis capable of contacting the rear end of said elongated load to movesaid rear end away from said aircraft at a controlled speed, said rearfluid jack module being independently attachable to said aircraft fromsaid front fluid jack module, fluid supply means on said aircraft forproviding a fluid under pressure, a control device which comprises arelease/ejection module which is attachable to said aircraft separatelyfrom said front fluid jack module and said rear fluid jack module andwhich includes an inlet channel, two outlet channels, and adouble-needle servo-slide valve movable between said two outlet channelsto control the ratio of fluid under pressure that flows through each ofsaid two outlet channels from said inlet channel, a first supply lineconnected between said fluid supply means and said inlet channel of saidcontrol device, second and third supply lines respectively connectedbetween said two outlet channels of said control device and saidrespective front and said rear fluid jacks, and detachment means fordetaching said elongated load from said support elements, saiddetachment means comprising a connection rod having a first endconnected to said release/ejection module and a second end, and a latchmeans attached to the second end of said connection rod, said latchmeans being cooperable with a boss on said elongated load to axiallymove said elongated load and cause detachment thereof from said supportelements upon axial movement of said connection rod by saidrelease/ejection module, said control device operating to control theratio of fluid under pressure that flows into said second and thirdsupply lines from said first supply line and thus the speed at whichsaid front and rear fluid jacks move said respective front and rear endsof said elongated load away from said aircraft and thus the angularpitching speed imparted to said elongated load.
 2. A mechanism asclaimed in claim 1, wherein said fluid supply means comprises a tankcontaining compressed air.
 3. A mechanism as claimed in claim 1, whereinsaid release/ejection module includes a piston chamber and a drivepiston movably mounted in said piston chamber, the first end of saidconnection rod being attached to said drive piston.
 4. A mechanism asclaimed in claim 1, wherein said release/ejection module includes abraking piston movably mounted in said piston chamber and fluid ductsextending between said inlet channel, said piston chamber and saiddouble-needle servo-slide valve, such that, prior to entering saiddouble-needle servo slide valve, the fluid under pressure from saidfirst supply line will cause said drive piston and said braking pistonto move within said piston chamber in such a manner that said connectionrod moves axially and then brakes to a full stop.